File sharpening machine



April 3, 1956 F. N. MOON ET A1.

FILE SHARPENING MACHINE 7 Sheets-Sheet l Original Filed Sept. 22. 1950INVENTORS FRANK N. Moa/v LYNN E. w/aLE April 3, 1956 F, N, MOON ET ALFILE SHARPENING MACHINE Original Filed Sept. 22. 1950 7 Sheets-Sheet 2April 31956 F. N. MOON ET AL 2,740,235

FILE SHARPENING MACHINE Original Filed Sept. 22. 1950 7 Sheets-Sheet 3llllf FEA/we N. Moo/v,

s/NN E. w/BLE,

April 3, 1956 F. N. MOON ET AL 2,740,235

FILE SHARPENING MACHINE Original Filed Sept. 22. 1950 7 Sheets-Sheet 4 Mo my Pw j i E i I i i WMM M w ME K V. EB .Q W M i-\\ A W Ele i April 3,1956 F. N. MOON ET AL FILE SHARPENING MACHINE m E. m i u Mm 0m w M. M Mwhw W W INN \wN.

April 3, 1956 F. N. MOON ET AL FILE SHARPENING MACHINE 7 Sheets-Sheet 6Original Filed Sept. 22, 1950 M. m QWI M E L LIN@ of aw M .E N n Y mL F@WN mw k. Nw h Qlwmw n mw .@Q f WW April 3, 1956 F. N. MOON ET AL FILESHARPENING MACHINE 7 Sheets-Sheet 7 Original Filed Sept. 22, 1950INVENTORS FRANK N. MOON LYNN E. WIBLE BY United States Patent O f'2,740,235 FLE SVIARPENNG MACHINE Frank N. Moon, Gil City, and Lynn E.Wible, Reno, Pa.V Snbsttlited for application No. 186,282, September 22,1950i. This application April 1', 1955, senat Ne. 498,722

10 Claims. (Cl. 51-58') This invention relates to file sharpeningmachines and more particularly to a machine for honing files to a sharpcondition.

It is among the objects of the invention to provide an improved lesharpening machine which will individually hone the iile teeth orserrations to a sharp condition, which will maintain the cutting edgesof the le substantially level, which will effectively hone curved leteeth or serrations, which is power operated, rapid and fully automaticin operation, which hones the le teeth in an oil bath, which has aplurality of easily replaceable honing elements, which is adjustable fordifferent concentricities of curved iile teeth, and which is strong anddurable in construction, economical to manufacture, and easy to use.

Other objects and advantages will become apparent from a considerationof the following description and the appended claims in conjunction withthe accomi panying drawings, wherein:

Figure l is a top plan view of a le sharpening Inachine illustrative ofthe invention, parts being broken away and shown in cross section tobetter illustrate the construction thereof;

Figure 2 is a side elevational view of the le sharpening machineillustrated in Figure 1, parts being broken away and shown in crosssection to better illustrate the construction thereof;

Figure 3 is an end elevational view of the le sharpening machineillustrated in Figures l and 2 looking at the right hand end of themachine as illustrated 'in these figures, parts being broken away andshown in cross section to better illustrate the construction of themachine;

Figure 4 is a transverse cross sectional view on the line 4--4 of Figure2;

Figure 5 is a longitudinal cross sectional view on the line 5--5 ofFigure 2;

Figure 6 is a transverse cross sectional view on the line 6 6 of Figure2;

Figure 7 is a fragmentary side elevational View on a somewhat enlargedscale with parts broken `away and shown in cross section to illustratethe mechanical details of the feed mechanism ot' the machine;

Figure 8 is a fragmentary cross sectional view on the line 8-8 of Figure2;

Figure 9 is a perspective view of vone-component /of a hone elementholding block constituting an operative component or" the machine;

Figure l0 is a perspective View of a leaf spring constituting acomponent of a holding block assembly;

Figure 11 is a perspective view of a hone element and hone elementholding block assembly;

Figure 12 is a perspective view of a plunger constituting an operativecomponent of the feed mechanism; and

Figure 13 is a perspective view of a spring inger also constituting anoperative component of the feed mechanism of the machine. n

With continued reference to the drawings, the numeral 10 indicates arectangular base plate 'of rigid construc- 2,740,235 Patented Apr. 3,1956 ICC 2 tion and conveniently formed of a plate of iron or steel ofsuitable thickness, although it may be formed of wood or other suitablematerial without in any way exceeding the scope of the invention.

Two end frame members 1.1 and 12 are mounted on the base plate andextend upwardly therefrom in spaced apart and substantially parallelrelationship to each other and substantially perpendicular to the baseplate. The end frame member 11 extends transversely of the base platenear one end of the latter and the end frame member 12 extendstransversely of the base plate between the frame member V11 and theother end of the base plate.

A table 13 in the form of a flat, rectangular plate, is mounted on theedges of the end frame members 11 and 12 remote from' the base plate 10and is spaced from and substantially parallel to the base plate.Brackets I4 and 15 are mounted on the table 13 directly above the endframe members 1'1 and 12 respectively and a pair of spaced apart andsubstantially parallel guide bars 16 and 17 are carried by the brackets14 and 15 above and substantially parallel to the table 13.

The brackets are. provided with spaced apart apertures and the two guidebars 16 and 17 have at their ends screw threaded reduced portionsextending through the apertures in the brackets and receiving nuts 18lto rigidly secure the guide bars to the brackets, these brackets beingrigidly secured to the frame end members 11 and 12 by suitable meanssuch as the studs I9.

Two slides 20 and` 21 are mounted in spaced apart relationship on theguide bars 16 and 17, each of these slides having spaced apart aperturestherein each of which slidably receives a corresponding guide bar. Theseslides are provided in their edges remote from the table 13 withrectangular notches or recesses and a le supporting bed plate 22 ismounted onthe slides 20 and 21.

The iile bed plate 22 is a rectangular metal bar of rectangular crosssectional shape having a length and width substantially equal to thelength and width of the iile to be sharpened on the machine and isrigidly secured to the slides 20 andi v21 by suitable means, such as thecap screws 23. The bar 2'2 is providedk with transversely extendinggrooves of inverted, T-shaped cross section located one near each end ofthe bar as indicated at 24 and 25. The le 26, of the type to besharpened by this machine, is provided with apertures extendingtherethrough, one near each end thereof which apertures register withthe grooves" 24 and 2S in the bed plate bar 22. Suitable rectangularnuts are slidably mounted in the wider portions of the grooves 24 and 25and screws, as indicated at 27 and 28y Figures 5, are inserted throughthe apertures in the file and threaded into the nuts received in thewider portions of the grooves to rigidly secure the ile to the bedplate.

Since the nuts for the screws 27 and `28 are slidably received iny theT-shaped grooves in `the bed plate, the le can be adjusted transverselyof the bed plate within suitable limits to properly center the file inthe machine.

The tile 26 is of the type used in' smoothing automobile bodies duringrepair work 'thereon and has coarse, arcua'tely curved teeth whichextend transversely across the le from one side' to the other. Thecenters of curvature of the le teeth lie on a common line extendinglongitudinally of the iile. ln' some iles' this line of centers extendsalong the mid-width location of the tile but, with di'ierent les, thisline may be displaced to either side of the mid-width location whichrenders' itnecessary to provide means for adjustably centering the ii'lerelative to the le sharpening machine.

The le supporting bed plate "22 is `surrounded by a rectangular oil 'pan29 which is secured to the lbed Iplate and extends above' the uppersurface yof the bed `plate a distance 'sufficient "to lmaintain a filemounted on the bed plate immersed in a bath of oil during the honingoperation. The iile teeth are thus honed under an oil bath whichprevents the cutting edges of the teeth from becoming overheated andalso carries away the cuttings or abrasive material so that the honingpoints or elements do not become clogged.

Four posts 3i?, 31, 32, and 33 are secured at their lower ends to therectangular table 13 one near each corner of the table and extendupwardly from the table subsstantially perpendicular thereto and a toolhead, generally indicated at 34, is supported by these posts above thetile supporting bed plate 22. Each of the posts is provided near itslower end with an annular collar 35 constituting a stop shoulder restingon the upper surface of the table plate 13 and with a screw threadedportion extending from this collar through a corresponding aperture inthe table plate. A nut 36 threaded on the end of the post at the lowerside of the table plate rigidly secures each post at its lower end tothe table. At a location just above the upper surface of the bed plate22 each post is provided with a second annular collar 37 and the toolhead 34 includes a rectangular bottom plate 38 having apertures thereinone near each corner and respectively receiving the posts 30, 31, 32 and33 above the corresponding stop collars 37. The posts extend above thebottom plate 38 and nuts 39 are threaded one on the upper end of eachpost. Spring abutment washers 4i) surround the posts immediately belowthe corresponding nuts 39 and coiled compression springs 41 respectivelysurround the posts between the corresponding abutment washers 413 andthe upper surface of the bottom plate 38.

The bottom plate 38 is provided with additional apertures located onenear each of the posts 3i), 31, 32 and 33, one substantially midwaybetween the posts and 33 and one substantially midway between the posts3l and 32 and bolts 41' are secured at their lower ends one in each ofthese additional apertures in the bottom plate 38. These bolts extendupwardly from the bottom plate 38 substantially perpendicular theretoand a top plate 42 is provided with apertures respectively receivingthese bolts. Spacer sleeves 43 surround the bolts between the bottomplate 38 and the top plate 42 and nuts 44 threaded on the bolts andbearing against the upper surface of the top plate 42 secure the plates38 and 42 together in spaced apart and substantially parallelrelationship to each other.

Guide blocks 45 of crescent shaped cross section are disposed in thespace between the bottom plate 38 and the top plate 42 and are equallyspaced apart with their partly cylindrical surfaces disposedperpendicular to the bottom and top plates of the two heads. These guideblocks are secured to the bottom plate i by suitable means such as thecap screws 46 and dowels 47 and 45 disposed one at each side of thecorresponding cap screw.

These guide blocks are mounted on the bottom plate 3S so that theconcave side of one block is opposed to the convex side of the adjacentblock and the spaces between adjacent blocks constitute curvedguideways, the mean curvature of which corresponds exactly to thecurvature of the teeth of the le.

The bottom plate 38 is provided with crescent shaped apertures 49disposed one between each two adjacent guide blocks for the projectionof honing points or elements through the bottom plate 38.

Hollow housings Sil are disposed one between each two adjacent guideblocks 45 for carrying the hone elements and hone holders. Each of thesehousings is a three part structure including a body portion 51 having arectangular recess in one side thereof and having its other sideexteriorly convex on a partly cylindrical curvature to lit thecylindrically curved concave face of the adjacent guide block 45, acover S2 which overlies the recess in the body portion 51 and has itsface remote from the body portion concavely curved on a partlycylindrical curvature to t the partly cylindrical convex. face of theadjacent guide block 45. The cover 52 is. secured to the body portion 51by suitable means, such, as screws, and a cap 53, particularlyillustrated in Figurey 9, is mounted on the end of each housing 5l)adjacent thel upper plate 42.

The cap 53 comprises a plate portion 54 of the same: shape as the upperend of the housing 5l) and having4 screw holes 55 therein for thereception of screws which attach the cap to the body portion 5ft andcover 52 of' the housing. The cap also includes a cylindrical pin 56projecting upwardly from the upper surface thereof.

When all of the housings 50 are mounted in the spaces between theadjacent guide blocks 45, the pins 56 will. be disposed in a rowextending longitudinally of the top plate #32 and contacting theundersurface of this plate. The ends of the housings opposite the pins56 ride on the upper surface of the bottom plate 38 around the apertures49 in the bottom plate so that the housings are supported in uprightposition in the tool head for sliding movement transversely of theplates 38 and 42 through the guideways between adjacent guide blocks 45.

lione element holders 57 are mounted one in each housing 54) and eachholder 57 carries a hone element 64 which projects from the holderthrough the corresponding aperture 49 in the plate 3S into contact witha file 26 supported on the bed plate 22 in the manner indicated above.

Each of the hone holders 57, as particularly illustrated in Figure 1l,comprises a rectangular metal block 59 having a beveled end and arectangular recess 61 in one face thereof opening to the beveled end,and a rectangular cover 62 which tits upon the recessed face of theblock 59 and has a beveled end 63 complementary to the beveled end 60 ofthe block 59. A honing element 64 of rectangular shape and having abeveled end 65 projecting from the beveled end of the holder is mountedin the recess 61 of the block 59 and secured therein by the cover 62.The honing element is secured in the holder against movement underordinary conditions by disposing a layer of thin sheet material, such aspaper, around the portion of the honing element received in the recess61 or by precoating this portion of the honing element with a coating ofmaterial such as a synthetic resin plastic.

The cover is secured to the block 59 by suitable means such as thescrews 66 extending through holes in the block and threaded into tappedholes in the cover and the cover 62 is provided at its end remote fromthe beveled end 63 with an outwardly projecting shoulder 67. The bodyportion 5l of the housing Sil is provided at its upper end with ashoulder receiving recess 63 and contact of the shoulder 67 with thebottom of this recess provides a limit stop for movement of the holder57 downwardly relative to the corresponding housing.

A longitudinally curved at spring 69 is disposed between the inner orundersurface of the housing cap 53 and the adjacent end of the holder 57to apply a downwardly directed resilient force to the holder andmaintain the associated honing element 67 in firm contact with a illebeing honed.

A rectangular head plate 7i) is slidably mounted in the space betweenthe top plate d2 of the tool head the adjacent ends of the guide blocks45 and has an elongated slot '73 extending longitudinally thereof andreceiving the pins 56 of the housings Sil which carry 'the hone holdersand honing elements. Guide brackets Il and 72 are secured to the headplate 7@ and overlap the respectively opposite ends of the top plate 42to hold the head plate against longitudinal movement relative to the topplate while permitting sliding movement of the head plate laterally ortransversely of the top plate 4.2.

A bar 74, shorter than the slot 73, is slidably disposed in this slotand has spaced apart apertures respectively receiving the pins 56 tomove the housings 59 back and forth in them guide'nays between guideblocks '45. The sliding of the bar 74 i'n slot 73 opense's fr 'thecurvature f the gide'ways.

Arbor pins 75 and 76 project outwardly from Vthe respectively oppositeends of the head plate 70 for a purpose to be presently described.`

A pair of standards 77 and 78 are secured to and einem upwardly from thebase' plaie 10 ai respectively opposite ends of the base plate and at'one side of the table plate is. An eceenfrie shaft 80 is journaled atits respectively opposite ends in the standards 77 and 78 at the upperends of 'the standards by suitablemeans, suchas the anti-friction ballbearings 81. A third standard 82 is 'mounted on the base plate at theside `of shaft 80 remote from the table plate 13 and has two upwardlyextending legs 83 and 84. IA main vdrive shaft 85 is journaled by meansof suitable anti-friction bearings 86 and *87 in the le'gs S3 and 84 'atthe upper ends of these legs. This main drive shaft 85 has on its endrernote from the shaft 80 a belt pulley 88 for receiving a belt by meansof which the main drive shaft 85 is drivingly connected to a suitablepower plant, such as an electric motor, mounted on the base plate 10.

A beveled pinion gear 90 is mounted on the end of main drive shaft 85remote from the belt pulley 8S and a beveled pinion gear 90 larger thanthe pinion 89 is mounted on the shaft 80 and meshes with the pinion 89to provide a driving connection from 'the shaft 85 t the shaft 80. Y

Eccentrics 91 and 92 are mounted on the shaft 80, one at each end of theshaft and at the outer sides of the standards 77 and 78 respectively andc onetig rods 93 and 94 connect the ec'centrics 91 and 92 to the arborpins 75 and 76 respectively on the head plate 70. The connecting rod 93has at one end ari aperture which rotatably receives the eccentric 91and has at its other end an aperture receiving an anti-friction rollerbearing' mounted on the arbor pin 75'. The connecting rod 94 also has atone end an aperture receiving the eccentric 92 and at its other end anaperture receiving an antifriction ball bearing 9S mounted on the arborypi'n 76. The ball bearing is secured on thel arbor pin between ashoulder on lthe latter and nuts 96 threaded onto the screw threadedouter end of the pin. An annular shoulder in the bearing receivingopening in the connecting rod bears against the innerl side of the outerrace of the bearing 95 and a plate 97 secured to the outer side of theconnecting rod has a nut receiving opening therein and a angesurrounding this opening and bearing against the outer side of the outerrace of the ball bearing to maintain the corresponding' end of theconnecting rod against movement relative to the outer race' of the ballbearing. The plate 97 is secured to the connecting rod by suitable meanssuch as screws, not illustrated;

The eccentric 92 is provided at its inner end adjacent the standard 78with an outwardly projecting annular ange providing a stop shoulder forthe inner side of the connecting rod 94 and a plate 98 is secured to theouter end of the eccentric by suitable screws 99 and marginally overlapsthe connecting rod 94 to hold the connecting rod between itself and thea'nge 100 on the inner end of the eccentric. The construction/of the'connecting rod 93 and associated bearing parts is the same as that ofthe connecting rod 94 and associated bearing parts, as described above.

With this arrangement, when the eccentric shaft 80 is driven by the maindrive shaft 85 through the gears 89 and 90, the eccentrics 91 and 92 andthe connecting rods 93 and 94 will impart a reciprocatoiy movement tothe head plate 70 in a lateral direction or transversely of the topplate 42 of the tool head. This will move the housings 50 back and forththrough the curved guideways between the adjacent guide blocks 45 andthis movementof vthe housings 50 will move the holders 57 and honingelements 64 back and forth in arcuately curved petits transversely offile supported on the tied plate z2. The shape f fue' guide blocks 45 issuch that the beveled ends of the honing e'lefnents 64 will eXac'tlyfollow the curvature or the' file teeth and theA guide'` blocks 45, thehtisirg's 50, the holders 57 and honing elements 64 are so dimensione'dthat the beveled ends of the honingelenieiits' are successively spacedapart the same distance which distance is equal to a predeterminednumb''r of successive tile' teeth.

" In the arrangement illustrated there are seven honing elements'. Itthese lements are' spaced apart a distance of seven successive iileteeth arid the lile has forty-nine or fifty teeth on one side, all ofthe iile teeth can be' honed in seven successive honing operations.

A bearing block is mounted on the base plate 10 adjacent the inner sideof the frame end member 11 and substantially parallel to the latter.This bearing blockhas two spaced apart bearing receiving aperturestherein in each of which is inountedan anti-frictionl ball bearing 106.l

A similar bearing block 107 is mounted on the base plate 10 spaced fromthe side of the end frame member 12 remote' from the member' Il andhaving spaced apart apertures Atherein receiving anti-friction ballbearings, as indicated at 108.-

Two cam shafts 109 and 110 are journaled in the antifriction bearingscarried by the bearing blocks 105 and 107 and are disposed in spacedapart and substantially parallel relationship between the base plate 10and the table plate 13 and substantially parallel to both of theseplates.

Two substantially cylindrical cams 111 and 112 are mounted n the shaft109 one near the bearing block 165 and one near the frame end member 12and two similar 'Canis 1'13 and 114 are mounted on the' shaft incorresponding positions. The main portion of the peripheral surface ofeach cam is substantially cylindrical but the cylindrical peripheralsurface is interrupted by a single carri lobe 115 which projectsoutwardly from the cylindrical surface and has flat side faces whichmutually converge from the cylindrical surface to the point or peak ofthe lobe and are inclined at different angles to a radius extending fromthe axis of rotation of the Cain through the peak of the cam lobe, theface at the back side of such radius in the direction of rotation of thecam being steeper than the face at the front side of the radius.` l

A worin wheel '116 is mounted on the shaft 1G19 between the frame endmember 12 and the bearing block 107 and a similar worm wheel 117 ismounted on the cam shaft 110 in the corresponding locations.

Bearing brackets 118 and 119 are mounted on the base plate 10' at theopposite ends of the space between the frame end member 12 and thebearing block 107 and these bearing brackets are provided near theirupper ends with openings receiving anti-friction ball bearings 120 and121 respectively. Apworm Shaft 122 is journaled in the bearings 120 and121 and is disposed immediately above the worm gears 116 and 117 and atright angles to the 'cam shafts 109 and 110.

Worns' 123 and 124 are provided onlthe shaft 122 and mesh with the woringears 116 and 117 respectively, 'the arrangement beingl such that theworin's and Worm gears` drive the shafts l109 and 110 at the saine speedin respectively opposite directions.

Bearing projections 125 and 126 are mounted on and projectperpendicularly outward from the standards 78 one near the eccentricyshaft 80 and the other between the worm shaft 122 and the base plate10. These extensions` arel provided with openings receivinganti-friction ball bearings- 127Mand 128 respectively and a verticallydisposed shaft 129 is journaled near its opposite ends in these ballbearings. A beveled gear 131B is secured on the upper end of thevertical shaft 129 and a beveled gear 131 materially smaller than thegear 130 is mounted on the shaft S and meshes with the gear 13b to drivethe vertical shaft 129 from the eccentric shaft 80.

A beveled gear 132 is secured on the end of the worm shaft 22 adjacentthe vertically disposed shaft 129 and a beveled gear 33 materiallysmaller than the gear i3?. is mounted on the shaft 129 and meshes withthe gear 132 to drive the worm shaft 122 at a speed greatly reduced fromthe speed of the eccentric shaft Si?. The worm and worm gear drivingconnections between the worm shaft 122 and the cam shafts 109 and H0further reduces the rotational speed of the cam shafts so that theeccentric shaft Sil makes a large number of revolutions for eachrevolution of each of the cam shafts.

Four lifts or tappets 135, 13o, 137 and 138, in the form of cylindricalpins, are slidably mounted in corresponding bearing bushings t39respectively received .in openings or apertures provided in the tableplate 13 one above each of the cams ill, 112, 113 and lid so that thelower end of each tappet rests on a corresponding cam. At the upper endsthe tappets have reduced portions extending through correspondingapertures provided in the bottom plate 38 of the toolhead and thisbottom plate is rigidly secured to the tappets by nuts 140 threaded ontothe reduced end portions of the tappets and bearing on the upper surfaceof the bottom plate 38.

The cams are set so that the cam lobes simultaneously contact the lowerends of all of the tappets to raise the tool head when the cam lobes arebrought under the tappets.

The operation of the mechanism is such that a predetermined number ofhoning strokes will be given to the honing elements ed and the tool headwill then be raised by the cams and tappets to lift all of the honingelements above the work surface of a tile being honed so that the ilecan be moved longitudinally to present new teeth to the honing elements.Suitable feeding means are operative while the honing elements arelifted :from the le to feed the file one tooth in its feeding directionto bring a new tooth into engagement with each of the honing elements.The file is thus periodically fed past the honing elements, apredetermined number of honing strokes being given to the teeth betweenthese feeding movements and the honing elements being lifted entirelyclear of the tile while the feeding of the le is being accomplished.

rl`he springs il on the posts 36, 3i, 32 and 33 resiliently urge thetool head downwardly at all times, maintaining the tappets or lifts 13S,136, 137 and L38 in lirm contact with the associated cams 11i, H3, H4and 112 and return the honing elements 64 to honing engagement with thetile after the tool head has been lifted by the cam lobes for a feedingmovement of the file.

A lever 41 is disposed at the outer side of the end frame member i2 andis pivotally connected intermediate its length by a pivot pin 'i421 to abracket M3 mounted on the member 12 at the corresponding end of thetable plate 13. An aperture 144 is provided in the frame member 1,2opposite the cam 112 and a screw threaded counterbore 145 is provided inthe side of the member l2 adjacent the cam. A hollow cylindrical nut.lido is threaded into the counterbore and a plunger 147 extends throughthis nut and through the aperture 144 in the member 12 and contacts atone end an abutment 143 carried by the lever 14l at the lower end of thelatter. An extension or lobe 149 is provided on the face of the cam 112facing the member 12 and this extension contacts the adjacent end of theplunger 147 when the cam lobes contact the tappets to raise the toolhead. An annular collar G is provided on the plunger 147 within the nut146 and a compression spring ll surrounds the plunger between thiscollar and the end of the counterbore 145 to maintain the plunger incontact with the adjacent face of the cam 112.

A spring linger li2, as particularly illustrated in Figure 13, issecured at one end to the upper end of the lever 141 and overlies theadjacent end portion of a tile 26 secured on the bed plate 22. Theringer 152 is a flat leaf spring having near one end an aperture 153which receives a screw 154 which attaches this end of the spring fingerto the upper end of the lever i411 The other or distal end of the lingeris bent downwardly, as indicated at :55 and the end is arcuately biasedto fit the curved teeth or serrations of the tile. With thisarrangement, when the projection 149 strikes the adjacent end of theplunger 147 the lever tdi is swung about the pivot pin id?. and forcesthe spring finger 152 in a direction to move the rile one tooth iu adirection away from the lever. As explained above, this occurs while thehoning elements 64 are lifted from the tile.

A coiled tension spring 156 is secured at one end to a pin 157 mountedin an aperture in the slide 2t) between the slide bars i6 and 17 andextends through an aperture i'provided in the siide 2l. At its other endthis r is connected by a pin 1532 to the bracket 15 supporting the guiderods and acts to resiliently urge the bed plate 22 and a 'lile mountedthereon toward the lever lill. This return movement of the tile isstopped by a second spring nger 16d mounted at one end on the upper endof an extension 'll projecting upwardly from the bracket 143.

"lhe pin 157 is extended from the slide 212 toward the adjacent ends ofthe slide bars M6 and 1.17 and a micro switch 162 is mounted on abracket i615 secured to the frame end member il, the micro switch beingpositioned for operation by the adjacent end of the pin 57 when the filehas been fed to its limiting position. The micro switch 152 is connectedinto the circuit of the machine driving motor in a manner toautomatically stop the operation of the machine when the honing of thetile has been completed.

A block 164 is mounted on the end of the bed plate 22 adjacent the feedlever 1.41 and is provided in its upper end with serrations or teethwhich continue the tile teeth somewhat beyond the adjacent end of thefile. This permits the corresponding end of the fle to be moved somewhatpast the hone element nearest the feed lever 141 so that, if the 'tilehas uneven number of teeth all of the teeth can be subjected to thehoning operation.

From the above description it will be noted that the machine is fullyautomatic in operation and will give each tooth of a tile apredetermined number of honing strokes and will then feed the tileforwardly one tooth to bring new teeth into engagement with the honingelements, the feed progressing step by step and one tooth at a time.When the honing of one side of the iile is completed, the screwssecuring the lile to the bed plate are removed and the tile is slippedout of the machine at the end of the machine remote from the feed leverand is turned over and replaced on the bed plate, the spring fingers le@and 52 being manually raised while the corresponding end portion of thefile is inserted thereunder.

The curved iile teeth are effectively honed from one end to the otherand are honed only on their sharpened edges so that the'edges of theteeth or serrations are maintained in a level or even condition and thetile is not rapidly Worn away as is the case with existing iilcsharpened methods.

This application is a substitute of application Serial No. 186,282,filed September 22, i), now abandoned.

Having thus described the invention, what is claimed as new is:

l. A file honing machine comprising a base, upright frame elementssupported on said base, spaced apart guide bars mounted on said frameelements, a iile supporting bed plate slidably mounted on said guidebars for longitudinal movement, a tool head mounted on said frameelements above said bed plate for movement toward and away from thelatter, guide blocks having cylindrically curved faces mounted in saidtool head in spaced apart relationship to provide therebetween curvedguideways corresponding to the curvature of the teeth of a le to aspring connected between said frame structure and said bed plateresiliently urging the latter in a direction opposite to said filefeeding direction, and a resilient nger mounted on said frame forengaging a file supported on said bed plate and holding said bed plateand a le supported thereon at the positions to which they are moved bysaid feed means.

6. A tile honing machine comprising a frame structure, a le supportingbed plate slidably mounted on said frame structure for longitudinalmovement relative to the frame structure, a tool head supported on saidstructure at one side of said bed plate and including spaced apart guideblocks having transversely curved adjacent faces providing curvedguideways therebetween, transversely curved housings disposed one ineach guideway for reciprocatory movement therein with their curved sidesin contact with the transversely curved faces of said guide blocks,honing elements carried one by each housing and projecting from saidhousings toward said bed plate, spring means acting between said framestructure and said tool head resiliently urging said honing elementstoward said bed plate, power operated means supported on said framestructure and connected to said housings for imparting reciprocatorymovement to the latter, cam means operated by said power operated meansand acting between said frame structure and said tool head forperiodically moving said honing elements away from said plate againstthe force of said spring means, and feed means mounted on said framestructure adjacent said bed plate and operated by said cam means toengage a tile supported on said bed plate and move said bed plate and ale supported thereon one tile tooth at a time during the intervals inwhich said honing eiements are moved away from said bed plate, saidpower operated means being effective to impart a predetermined number ofreciprocatory movements to sai-:l honing element housings betweensuccessive operations of said cam means to move said honing elementsaway from said bed plate.

7. in a file honing machine, a tool head including spaced apart guideblocks having cylindrical curved opposing faces providing curvedguideways therebetween,

hollow housings disposed one in each guideway for reciprocatory movementtherein and having cylindrically curved faces slidably engaging thecylindrically curved faces of adjacent guide blocks, honing elementholders disposed one in each housing and projecting at one end from oneend of the latter, and honing elements mounted one in each holder andprojecting from said one end of the latter.

8. in a tile honing machine, a tool head including spaced apart guideblocks having cylindrically curved opposing faces providing curvedguideways therebetween, hollow housings disposed one in each guidewayfor reciprocatory movement therein and having cylindrically carved facesslidably engaging the cylindrically curved faces of adjacent guideblocks, honing element holders disposed one in each housing andprojecting at one end rom one end o'r the latter, honing elementsmounted one in each holder and projecting from said one end of thelatter, springs disposed one in each housing and acting between thehousings and the associated holders to resiliently urge said holdersoutwardly of the corresponding housings, and stop shoulders on saidhousings and said holders limiting movement of said holders outwardly ofthe corresponding housings.

9. A tile honing machine comprising a frame structure, a file supportingbed plate slidably mounted on said frame structure for longitudinalmovement relative to the frame structure, a tool head supported on saidframe structure at one side of said bed plate and including spaced apartguide blocks having transversely curved adjacent faces providing curvedguideways therebetween, transversely curved housings disposed one ineach guideway for reciprocatory movement therein with their curved sidesin contact with the transversely curved faces of said guide blocks,honing elements carried one by each housing and projecting from saidhousings toward said bed plate, spring means acting between said framestructure and said tool head resiliently urging said honing elementstoward said bed plate, power operated means supported on said framestructure and connected to said housings for irnparting reciprocatorymovement to the latter, cam means operated by said power operated meansand acting between said framc structure and said tool head forperiodically moving said honing elements away from said plate againstthe force of said spring means, and feed means mounted on said framestructure adjacent said bed plate and operated by said cam means toengage a tile supported on said bed plate and move said bed plate and ale supported thereon one le tooth at a time during the intervals inwhich said honing elements are moved away from said bed plate, saidpower operated means including a shaft journaled on said framestructure, eccentrics on said shaft at spaced apart locationstherealong, a head plate engaging said housings, and connecting rodsconnecting said eccentrics to said head plate to impart lateralreciprocatory movement to the latter.

l0. A tile honing machine comprising a frame structure, a tilesupporting bed plate slidably mounted on said frame structure forlongitudinal movement relative to the frame structure, a tool headsupported on said frame structure at one side of said bed plate andincluding f spaced apart guide blocks having transversely curvedadjacent faces providing curved guideways therebetween, transverselycurved housings disposed one in each guideway for reciprocatory movementtherein with their curved sides in contact with the transversely curvedfaces or" said guide blocks, honing elements carried one by each housingand projecting from said housings toward said bed plate, spring meansacting between said frame structure and said tool head resilientlyurging said honing elements toward said bed plate, power operated meanssupported on said frame structure and connected to said housings forimparting reciprocatory movement to the latter, cam means operated bysaid power operated means and acting between said frame structure andsaid tool head for periodically moving said honing elements away fromsaid plate against the force of said spring means, and feed meansmounted on said frame structure adjacent said bed plate and operated bysaid cam means to engage a tile supported on said bed plate and movesaid bed plate and a file supported thereon one tile tooth at a timeduring the intervals in which said honing elements are moved away fromsaid bed plate, said cam means including a pair of substantiallyparallel cam shafts journaled on said frame structure, single lobe camson said cam shafts at spaced apart locations therealong, tappetsslidably mounted in said frame structure and each contacting acorresponding cam at one end and secured at its other end to said toolhead, worm gears secured one on each cam shaft at corresponding ends ofsaid cam shafts, a worm shaft journaled in said frame structure anddisposed substantially at right angles to said cam shafts, and worms onsaid worm shaft meshing respectively with said worm gears.

References Cited in the file of this patent UNITED STATES PATENTS1,131,999 Denley et al Mar. 16, 1915 .1,441,392 Bastian Ian. 9, 19231,777,135 Barley Sept. 30, 1930 2,212,999 Faulder Aug. 27, 19402,222,034 Jackson Nov. 19, 1940 2,627,143 Beyer Feb. 3, 1953 2,694,882Edwards Nov. 23, 1954 FOREIGN PATENTS 15,322 Great Britain June 30, 1909131,637 Switzerland June 1, 1929 377,383 Great Britain July 28, 1932432,026 Great Britain July 15, 1935

